/*
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getlogin.c	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/getlogin.c,v 1.11 2009/12/05 19:04:21 ed Exp $");

#include <sys/param.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "namespace.h"
#include <pthread.h>
#include "un-namespace.h"

#include "libc_private.h"

extern int __getlogin(char *, int);

__private_extern__ pthread_mutex_t __logname_mutex = PTHREAD_MUTEX_INITIALIZER;
__private_extern__ char *__logname = NULL;

static char *
getlogin_basic(int *status)
{
	if (__logname == NULL) {
		__logname = calloc(1, MAXLOGNAME);
		if (__logname == NULL) {
			*status = ENOMEM;
			return (NULL);
		}
	}

	if (__logname[0] == 0) {
		if (__getlogin(__logname, MAXLOGNAME) < 0) {
			*status = errno;
			return (NULL);
		}
	}
	*status = 0;
	return (*__logname ? __logname : NULL);
}

char *
getlogin(void)
{
	char	*result;
	int	status;

	pthread_mutex_lock(&__logname_mutex);
	result = getlogin_basic(&status);
	pthread_mutex_unlock(&__logname_mutex);
	return (result);
}

int
getlogin_r(char *logname, size_t namelen)
{
	char	*result;
	int	status;

	pthread_mutex_lock(&__logname_mutex);
	result = getlogin_basic(&status);
	if (status == 0) {
		if (strlcpy(logname, __logname, namelen) > namelen) {
			status = ERANGE;
		}
	}
	pthread_mutex_unlock(&__logname_mutex);

	return (status);
}
